16. London Zoo
London Zoo is the oldest and one of the most famous zoos our planet has. It started its journey way back in 1828. Initially, it was a centre of scientific studies on animals, but later in 1847 it started allowing public entry. Right now, the zoo is home to as many as 755 species. Some of the most prominent ones among them are Sumatran tigers, death adders, Sloth bears, Asian lions, Komodo dragons etc.